一条直线经过2个点(X1, Y1), (X2, Y2), X1<0, Y1>0, 这条直线的slope为正,问下面哪个正确
I、 X2<0 , Y2>0
II、X2>0, Y2>0
III、X2>0, Y2<0
选I和III
应该是I和II吧,一画图就看出来了,III是不可能的
有500辆车分两层停放,15%不是黄色。问第一层有多少车不是黄色。
条件1:第二层有XX辆车不是黄色
条件2:第一层是YY辆车是黄色。
A.500*15%-XX=第一层不是黄色的车。B 不可以。
x-y=8, x<4?
1) x+y>0
2) xy<0
A. because x+y>0, therefore, 8+y+y>0, then we can get y>-4. so x>4.
B. Xy<0. in a x-y plane, we can draw a line y=x-8, so we can se that if xy<0, 0<x<8. can not determine whether x<4
Therefore, the answer should be A.
A. because x+y>0, therefore, 8+y+y>0, then we can get y>-4. so x>4.
B. Xy<0. in a x-y plane, we can draw a line y=x-8, so we can se that if xy<0, 0<x<8. can not determine whether x<4
Therefore, the answer should be A.
条件1:第二层有XX辆车不是黄色
条件2:第一层是YY辆车是黄色。
A.500*15%-XX=第一层不是黄色的车。B 不可以。
x-y=8, x<4?
1) x+y>0
2) xy<0
A. because x+y>0, therefore, 8+y+y>0, then we can get y>-4. so x>4.
B. Xy<0. in a x-y plane, we can draw a line y=x-8, so we can se that if xy<0, 0<x<8. can not determine whether x<4
Therefore, the answer should be A.
A. because x+y>0, therefore, 8+y+y>0, then we can get y>-4. so x>4.
B. Xy<0. in a x-y plane, we can draw a line y=x-8, so we can se that if xy<0, 0<x<8. can not determine whether x<4
Therefore, the answer should be A.